Roger Federer and Rafael Nadal could renew their rivalry in the final of the Australian Open
Roger Federer has been out of action since July, having taken the rest of 2016 off to recover from a knee injury.
But having cruised past Mischa Zverev in the quarter-final, the Swiss is on course for a fifth Australian Open final.
There he could face Nadal, back in the last four of a Grand Slam for the first time in three years, and former world No 1 Andy Roddick believes it could be decisive in their battle for supremacy.
Roger Federer and Rafael Nadal last met in a major final at the French Open in 2011
"If you think of where they are at in terms of Federer being on 17 Slams and Nadal on 14 Slams, a Nadal win puts him back in the game, back in the conversation, narrowing the gap to 17-15 with the French Open just around the corner," Roddick said,
"A Federer wins puts him on to 18 and I don't know that there's enough time left to make up that difference, and he would sit on that record for a long time.
"In-form, playing well, bit of a throwback, it would be amazing.
"If it happens, it has to be the most important match in Australian Open history and possibly Grand Slam history."
Roddick was inducted into the tennis hall of fame before Federer's quarter-final on Tuesday.
The American won the US Open in 2003 but it was his only Grand Slam title as he went on to lose his four other finals to Federer.
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But Roddick bears no grudge against the Swiss.
“It’s weird because you share history with someone," Roddick added.
"It becomes a part of your definition for a long time.
“I’m happy that a part of my definition is as respectful, as classy and as good of a human as Roger.”